The hardware design technique for ultrasonic process tomography system

This paper describes a work carried out to design and development an ultrasonic process tomography system. The hardware design technique is of interest of this paper. A number of 32-ultrasonic transducers have been employed and the interrogation of ultrasonic information is based on transmission-mode approach. The hardware design technique including the signal processing methodology and the data acquisition technique has been detailed. An embedded controller has been used on each channel to simplify the hardware design as well as for system synchronization. An auto-calibration approach has also been used to calibrate 544 signals information. At the end of the paper, several tomograms reconstructed using the sensor array is discussed

Ultrasonic sensor for imaging measurement techniques

Generally, are many methods for imaging measurement techniques, traditional and modern method and still have pros and cons between these two ways. Basically, the traditional techniques method is reported does not fully meet the specification of modern industry nowadays. Traditional method mainly includes electromagnetic detection, eddy current testing and etc. Differ with the modern method which is using the ultrasonic for imaging techniques and involving the laser ultrasonic, ultrasonic velocity, real time ultrasonic and off axis propagation of ultrasonic which be define the modern method is widely used industry to improve from the traditional method. Rumoured has been widely separate that modern techniques of imaging measurement are gaining popularity from every industry such as in medical instrument, construction instrument, synthetic aperture and holographic imaging measurement. Modern industry has proposed various method in using the ultrasonic in order to improve the quality of work in industry. Several advantages have been discovered while using the ultrasonic industry such as in mediation which is ultrasonic is used to improve the imaging in human soft tissue, meanwhile in construction ultrasonic giving an advantage in defect detection in specific information such as the location on defection and the size of defection. Besides that, in real time ultrasonic imaging is giving an advantage in focusing for multi-layered objects with synthetic aperture and lastly ultrasonic also give an advantage in guided wave in thin orthotropic layers which is its been use for dynamic holographic imaging measurement

Segmented capacitance tomography electrodes: a design and experimental verifications

A segmented capacitance tomography system for real-time imaging of multiphase flows is developed and pre-sented in this work. The earlier research shows that the electrical tomography (ECT) system is applicable in flow visualization (image reconstruction). The acquired concentration profile ob-tained from capacitance measurements able to imaged liquid and gas mixture in pipelines meanwhile the system development is designed to attach on a vessel. The electrode plates which act as the sensor previously has been assembled and fixed on the pipeline, thus it causes obscurity for the production to have any new process installation in the future. Therefore, a segmented electrode sensor offers a new design and idea on ECT system which is portable to be assembled in different diameter sizes of pipeline, and it is flexible to apply in any number due to different size of pipeline without the need of redesigning the sensing module. The new ap-proach of this sensing module contains the integration intelligent electrode sensing circuit on every each of electrode sensors. A microcontroller unit and data acquisition (DAQ) system has been integrated on the electrode sensing circuit and USB technology was applied into the data acquisition system making the sensor able to work independently. Other than that the driven guard that usually placed between adjacent measuring electrodes and earth screen has been embedded on the segmented electrode sensor plates. This eliminates the cable noise and the electrode, so the signal conditioning board can be expanded according to pipe diameter

Optical tomography: Image improvement using mixed projection of parallel and fan beam modes

Mixed parallel and fan beam projection is a technique used to increase the quality images. This research focuses on enhancing the image quality in optical tomography. Image quality can be defined by measuring the Peak Signal to Noise Ratio (PSNR) and Normalized Mean Square Error (NMSE) parameters. The findings of this research prove that by combining parallel and fan beam projection, the image quality can be increased by more than 10%in terms of its PSNR value and more than 100% in terms of its NMSE value compared to a single parallel beam

Small Scale Non-Invasive Imaging Using Magnetic Induction Tomography - Hardware Design

This study is conducted to preliminary image the conductivity profile through the development of small scale non-invasive Magnetic Induction Tomography (MIT) system.  It is proved that the Magnetic Induction Tomography interested in mapping the passive electrical properties of materials; conductivity (σ), permittivity (ε) and permeability (µ) in both process and medical tomography.  The system is realized by designing the functional ferrite-core coil sensors, electronic measurements circuits for excitation and receiving coil, data acquisition system for transferring the data to the PC and suitable image reconstruction algorithm for providing the conductivity distributions measurement. The important characteristic for excitation coil is the one that can maintain the stability the optimum sine wave frequency ranging from 400 kHz up to 10 MHz.  The sine waves are fed to the excitation coil through the application of high current amplifier component respectively. In the experiments, the copper phantom represent as high conductivity material were placed into the region of interest.  The initial 16 channel MIT consists of 8 excitation coil and 8 receiving coil stacked alternately.  On the receiving circuit, the major problem is the weak secondary signal perturbation sensed by the receiving coil has been improved by placing the variable amplifier on each receiver. The enhancement of conductivity profile imaging has been made by using a common Linear Back Projection (LBP) algorithm.  The measurement was done on single and dual arrangement of copper phantom aligns in random coordinate so that the sensitivity of the excitation and receiving coil sensor can be experimentally observed.  The imaging’s results show that the hardware’s and algorithm used was capable to process the data captured at the receiver.  The results obtained can be useful for further improvement and research towards magnetic induction tomography

Modelling ultrasonic sensor for gas bubble profiles characterization of chemical column

In this paper, we present a modelling and experimental work to characterize gas bubble profiles in chemical column using a pair of ultrasonic sensor. The gas bubble profiles from 2.90 mm to 7.50 mm diameter are of interest in this study. The modelling concerns ultrasonic investigation via transmission- mode technique. The modelling estimation was compared with the experimental data and the gas bubble profile characterizations from the chemical column were deduced

Corrosion detection using piezoelectric wafer active sensors

In everyday life, the various sectors and activities are vulnerable to the effects of corrosion such as water supply sector, the industrial sector involving pipelines and oil and gas sectors. Reaction of electrochemical oxidation of the metal in reaction with an oxidant such as oxygen or sulfur is the main cause of corrosion. The various studies carried out to determine whether the condition of a material can be used or dangerous to use. Currently, there are two categories that are appropriate to solve this problem that is internal or external inspection. The first category of internal inspection, scanning is focused on one point, which is a method common to use the pipeline; it's mounted on a rotating transducer. The second category is the external inspection, this method is able to scan the parallel point, but when pipes are in use have the insulator, the insulator must be removable for the purpose of scanning and reinstall when finished scanning [1]. There are various methods that have been used in improving the reading count this corrosion. Among these are pitch-catch method that is used to detect corrosion on aluminum structures, pulse-echo method to detect corrosion in pipes and guided ultrasonic waves combined with BEM numerical simulation is used to detect hidden corrosion [2]. This paper will present multiple modes in-situ method using Piezoelectric Wafer Active Sensors transducers with impedance, pitch-catch and pulse-echo damage detection method for either corrosion or cracks in metallic plate structures [3] [4]

Miniaturized planar tomography for multiphase stagnant sample detection

Miniaturized device offers portability, high throughput and faster time response compared to macroscale devices. In microdevices, most of the application utilizes planar electrode for microanalysis process as it is inexpensive, highly controllable system and easy for installation. In addition, miniaturized planar sensor offers great potential for microscale medical diagnosis, chemical analysis, environmental analysis, cell culture application and single cell measurement using tomography measurement. In this project, a miniaturized planar tomography system is developed for multiphase sample detection such as liquid-solid and liquid-liquid. Eight-electrode device was fabricated on the copper plated printed circuit board (PCB) using the commercial fabrication technique. The ability of the proposed device in reconstructing images of a multiphase sample using Linear Back Projection algorithm is tested. Experimental results show that the reconstructed images closely resemble with the cross-section of the stagnant multiphase sample

Study and design of an ultrasonic flow tomographic front-end multi level measurement system

With the rapid evolution of electro-acoustical technology, ultrasonic tomography has made considerable progress in industry. An ultrasonic tomography system provides non-invasive and non-intrusive flow visualisation that enhances the understanding of fluid flow processes. The function of ultrasonic tomography is to continuously monitor the dynamics of liquid flow without interrupting the flow. The ultrasonic tomography technique is fully supported by a front-end hardware system. The front end is defined as all the hardware circuitries, including the ultrasonic transducer up to the Analogue-to-Digital Convertors (ADCs), even though the primary focus is the analogue signal processing components. We present here the challenges and trade-offs in the implementation of a front-end system by first explaining the basic operation of such a system, and then indicating what particular performance parameters are needed to ensure optimal system operation. Based on the results from our research studies, we propose an improved front-end multi-level solution that is more accurate than previous solutions and provides real-time measurement capability